Existing circuit-breaker devices for electrochemical storage cells taken individually, or associated to form a module or battery of cells (an assembly comprising at least one module), and located outside said storage cell are generally designed to break a circuit when the current being delivered is of the order of a few amps, typically 1 A to 2 A. Such devices act in the event of an anomaly in the operation of said electrochemical storage cell, typically an increase in pressure and/or temperature, e.g. due to the storage cell being overcharged or overdischarged. However, when the delivered currents are significantly higher, such circuit breaker devices are no longer effective, in particular because of the larger section of wire that needs to be broken.
Also, circuit breaker devices used when high currents are delivered by electrochemical storage cells taken individually, or more generally when cells are associated in the form of a battery, are fuse type circuit breaker devices, and they suffer from the drawbacks of being relatively slow (a few seconds between an anomaly being detected and the circuit being broken), and above all of completely preventing any further flow of electricity, thereby putting the entire battery associated with said cell out of circuit, whenever the cell forms part of a battery.
Thus one of the problems which arises is that of finding a device suitable for breaking the circuit in the event of a given storage cell delivering an excessively high current, typically 40 amps to 150 amps, and that is capable of acting as a complete shunt, i.e. that is capable, in the event of the storage cell operating anomalously, of putting a bypass conductor in place in parallel with the disconnected cell for the purpose of carrying substantially all of the current that was previously passing through the cell. Another of the problems posed is that of finding a circuit breaker device that is reliable and relatively fast, without being dangerous for the user.
Finally, another problem which is posed is that of making a device that ensures good electrical contact for the electrical connections of a cell while it is in normal use prior to any operating anomaly. This problem is particularly critical when high currents are delivered. In particular, it is advantageous to have connections that are reliable and safe, where the electrical contacts do not increase electrical resistance and do not oxidize.